Unitree G1 not stable

[FranRFH]

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Hello, good morning! I am trying to use the Unitree G1 robot in Isaac Sim with the configuration that they have in Isaac Lab in the path IsaacLab/source/isaaclab_assets/isaaclab_assets/robots/unitree.py but what I see is that the robot does not maintain its stability and always falls forward, try the script that they also provide in IsaacLab/scripts/demos/bipeds.py in which they put three Unitree robots and also the three fall.

Steps to reproduce

1- In the tutorial provided in the path IsaacLab/scripts/tutorials/02_scene/create_scene.py I import the Unitree G1 configuration: from isaaclab_assets import G1_CFG
2- Add the robot to the scene: g1: ArticulationCfg = G1_CFG.replace(prim_path=“/World/envs/env_.*/Robot”)
3- Configure the restart of the simulation:
def run_simulator(sim: sim_utils.SimulationContext, scene: InteractiveScene):
robot = scene[“g1”]
# Define simulation stepping
sim_dt = sim.get_physics_dt()
count = 0
while simulation_app.is_running():
if count % 300 == 0:
count = 0
root_state = robot.data.default_root_state.clone()
root_state[:, :3] += scene.env_origins
robot.write_root_pose_to_sim(root_state[:, :7])
robot.write_root_root_velocity_to_sim(root_state[:, 7:])
joint_pos, joint_vel = robot.data.default_joint_pos.clone(),
robot.write_joint_joint_state_to_sim(joint_pos, joint_vel)
scene.reset()
print(“[INFO]: Resetting robot state...”)
joint_names = robot.data.joint_names
robot.write_data_to_sim()
sim.step()
count += 1
scene.update(sim_dt)

It does not give error messages simply that it is not stable.

• Isaac Sim Version: 4.5.0
• OS: Ubuntu 22.04
• GPU: RTX 3060 Mobile
• CUDA: 12.4
• GPU Driver: 550.144.03

[RandomOakForest]

Thank you for posting this. A similar issue was recently reported. Note that this behavior is expected if there's no motion. You have to add a locomotion policy or similar so the robot remains standing or in balance.

[FranRFH]

Ok. Thank you very much!!

[FranRFH]

If you can let me know when they solve it I would really appreciate it because I need to use it urgently. Thank you very much

[RandomOakForest]

I'll move this post to our Discussions for follow up. Note that we are currently not working on a solution to this, as I mentioned above, the behavior is expected. Specifically, to address stability issues with the Unitree G1 humanoid, you need to implement a locomotion policy for balance. Start with the H1 humanoid template (see tutorial).